Compilare: main.cpp: In function 'int main()': main.cpp:43:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sir.length(); i++) ~~^~~~~~~~~~~~~~ main.cpp: In function 'int Calc(char, int, int)': main.cpp:31:1: warning: control reaches end of non-void function [-Wreturn-type] } ^